[ https://issues.apache.org/jira/browse/MAPREDUCE-1831?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Scott Chen updated MAPREDUCE-1831: ---------------------------------- Attachment: MAPREDUCE-1831.v1.1.txt > Delete the co-located replicas when raiding file > ------------------------------------------------ > > Key: MAPREDUCE-1831 > URL: https://issues.apache.org/jira/browse/MAPREDUCE-1831 > Project: Hadoop Map/Reduce > Issue Type: Improvement > Components: contrib/raid > Affects Versions: 0.22.0 > Reporter: Scott Chen > Assignee: Scott Chen > Fix For: 0.22.0 > > Attachments: MAPREDUCE-1831.txt, MAPREDUCE-1831.v1.1.txt > > > In raid, it is good to have the blocks on the same stripe located on > different machine. > This way when one machine is down, it does not broke two blocks on the stripe. > By doing this, we can decrease the block error probability in raid from > O(p^3) to O(p^4) which can be a hugh improvement. > One way to do this is that we can add a new BlockPlacementPolicy which > deletes the replicas that are co-located. > So when raiding the file, we can make the remaining replicas live on > different machines. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.